This invention relates to automatic machining centers and has as its principal object to provide a machining center which is so completely automated that it can be reliably operated unattended and unwatched for an entire shift.
Numerically controlled automatic machining centers have been manufactured in the past which can automatically perform a preprogrammed sequence of machining operations. Such machining centers have a plurality of tools which are stored in a tool magazine and are automatically inserted into and removed from the spindle to perform the corresponding machining operations. A machining center of this type is disclosed in U.S. Pat. No. 3,704,510, issued to Robert K. Sedgwick et al, for a "MACHINE TOOL WITH TOOL CHANGER". However, this type of automatic machining center requires the services of a full time operator for loading and unloading the workpieces, starting and stopping the machine for each machining cycle, cleaning out chips, inspecting the tools for excessive wear and breakage, replacing broken or excessively worn tools, compensating for tool wear, etc.
Automatic workpiece handling apparatus has been manufactured in the past, as disclosed in U.S. Pat. No. 3,825,245, issued to John G. Osburn et al, for a "WORKPIECE CHANGER MECHANISM FOR A MACHINE TOOL", and in U.S. Pat. No. 3,796,163, issued to Ronald E. Meyer et al, for a "MANUFACTURING SYSTEM", but such apparatus also requires the services of one or more full time operators.
Apparatus for automatically inspecting tools for excessive wear and breakage and for automatically replacing broken or excessively worn tools has been devised in the past as disclosed in U.S. Pat. No. 3,817,647, issued to Jerome H. Lemelson, for a "TOOL CONTROL ARRANGEMENT", and in U.S. Pat. No. 3,963,364, issued to Jerome H. Lemelson, for a "TOOL CONTROL SYSTEM AND METHOD". However, the machine tools disclosed in the Lemelson patents also require the attention of an operator. In spite of the great strides that have been made in automating machining operations, no prior art machine tool or machining center is known which is capable of operating unattended and unwatched for an entire shift or longer.